Catalyst for olefin polymerization

ABSTRACT

The present invention relates to a catalyst for olefin polymerization. Specifically, the present invention relates to a hybrid catalyst comprising different transition metal compounds and capable of preparing a polyolefin, particularly a linear low-density polyethylene, which has excellent processability, impact strength, and haze.

TECHNICAL FIELD

The present invention relates to a catalyst for olefin polymerization.Specifically, the present invention relates to a hybrid catalystcomprising different transition metal compounds and capable of preparinga polyolefin, particularly a linear low-density polyethylene, which hasexcellent processability, impact strength, and haze.

BACKGROUND ART

A metallocene catalyst, which is one of the catalysts used in thepolymerization of olefins, is a compound in which a ligand such ascyclopentadienyl, indenyl, and cycloheptadienyl is coordinated to atransition metal or a transition metal halide compound. It has asandwich structure in its basic form.

In a Ziegler-Natta catalyst, which is another catalyst used in thepolymerization of olefins, the metal component serving as the activesites is dispersed on an inert solid surface, whereby the properties ofthe active sites are not uniform. On the other hand, since a metallocenecatalyst is a single compound having a specific structure, it is knownas a single-site catalyst in which all active sites have the samepolymerization characteristics. A polymer prepared by such a metallocenecatalyst is characterized by a narrow molecular weight distribution anda uniform distribution of comonomers.

Meanwhile, a linear low-density polyethylene (LLDPE) is produced bycopolymerizing ethylene and an alpha-olefin at a low pressure using apolymerization catalyst. It has a narrow molecular weight distributionand short chain branches (SCBs) having a certain length, but generallydoes not have long chain branches (LCBs). Films prepared from a linearlow-density polyethylene have high strength at breakage, elongation,tear strength, and impact strength in addition to the characteristics ofcommon polyethylenes. They are widely used for stretch films and overlapfilms to which conventional low-density polyethylenes or high-densitypolyethylene are difficult to be applied.

When a linear low-density polyethylene produced by a metallocenecatalyst has excellent processability and haze of a film, the strengthof the film tends to decrease. On the other hand, when the film hasexcellent strength, the processability and haze tend to decrease.

Accordingly, there has been a need for a metallocene catalyst forpreparing a polyolefin having excellent processability and capable ofproviding a film with excellent impact strength and haze.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

An object of the present invention is to provide a metallocene catalystfor preparing a polyolefin, particularly a linear low-densitypolyolefin, having excellent processability as well as excellent impactstrength and haze.

Technical Solution

According to an embodiment of the present invention for achieving theobject, there is provided a catalyst for olefin polymerization, whichcomprises a first transition metal compound represented by Formula A anda second transition metal compound represented by Formula B.

In Formulae A and B, n and o are each an integer of 0 to 2, providedthat at least one of them is not 0, and m and 1 are each an integer of 0to 4,

M is titanium (Ti), zirconium (Zr), or hafnium (Hf),

X is each independently halogen, C₁₋₂₀ alkyl, C₂₋₂₀ alkenyl, C₂₋₂₀alkynyl, C₆₋₂₀ aryl, C₁₋₂₀ alkyl C₆₋₂₀ aryl, C₆₋₂₀ aryl C₁₋₂₀ alkyl,C₁₋₂₀ alkylamido, C₆₋₂₀ arylamido, or C₁₋₂₀ alkylidene,

Q is carbon (C), silicon (Si), germanium (Ge), or tin (Sn),

R¹ to R⁷ are each independently substituted or unsubstituted C₁₋₂₀alkyl, substituted or unsubstituted C₂₋₂₀ alkenyl, substituted orunsubstituted C₆₋₂₀ aryl, substituted or unsubstituted C₁₋₂₀ alkyl C₆₋₂₀aryl, substituted or unsubstituted C₆₋₂₀ aryl C₁₋₂₀ alkyl, substitutedor unsubstituted C₁₋₂₀ heteroalkyl, substituted or unsubstituted C₃₋₂₀heteroaryl, substituted or unsubstituted C₁₋₂₀ alkylamido, substitutedor unsubstituted C₆₋₂₀ arylamido, substituted or unsubstituted C₁₋₂₀alkylidene, or substituted or unsubstituted C₁₋₂₀ silyl,

at least one of R¹ and R² is independently linked to adjacent groups toform a substituted or unsubstituted saturated or unsaturated C₄₋₂₀ ring,and

R³ to R⁷ may each independently be linked to adjacent groups to form asubstituted or unsubstituted saturated or unsaturated C₄₋₂₀ ring.

Specifically, in Formulae A and B, n and o are each 1 or 2, m and 1 areeach 1, X is each independently halogen, M is zirconium, Q is carbon,and at least one of R¹ and R² is independently linked to adjacent groupsto form a substituted or unsubstituted unsaturated C₄₋₂₀ ring, R³ to R⁵are each C₁₋₂₀ alkyl, and R⁶ and R⁷ are each C₆₋₂₀ aryl.

Preferably, the compound represented by Formulae A and B may be acompound represented by Formulae A-1 and B-1, respectively.

Preferably, the catalyst for olefin polymerization comprises the firsttransition metal compound and the second transition metal compound at aweight ratio of 20:1 to 1:20.

The catalyst for olefin polymerization according to an embodiment of thepresent invention may further comprise a cocatalyst compound selectedfrom the group consisting of a compound represented by Formula 1, acompound represented by Formula 2, and a compound represented by Formula3.

In Formula 1, n is an integer of 2 or more, and R_(a) may eachindependently be halogen, C₁₋₂₀ hydrocarbon, or C₁₋₂₀ hydrocarbonsubstituted with halogen. Specifically, R_(a) may be methyl, ethyl,n-butyl, or isobutyl.

In Formula 2, D is aluminum (Al) or boron (B), and R_(b), R_(c), andR_(d) are each independently halogen, C₁₋₂₀ hydrocarbon, C₁₋₂₀hydrocarbon substituted with halogen, or C₁₋₂₀ alkoxy. Specifically,when D is aluminum (Al), R_(b), R_(c), and R_(d) may each independentlybe methyl or isobutyl, and when D is boron (B), R_(b), R_(c), and R_(d)may each be pentafluorophenyl.

[L-H]⁺[Z(A)₄]⁻ or [L]⁺[Z(A)₄]⁻  [Formula 3]

In Formula 1, n is an integer of 2 or more, and R_(a) may eachindependently be a halogen atom, C₁₋₂₀ hydrocarbon, or C₁₋₂₀ hydrocarbonsubstituted with halogen.

In Formula 2, D is aluminum (Al) or boron, and R_(b), R_(c), and R_(d)are each independently a halogen atom, C₁₋₂₀ hydrocarbon, C₁₋₂₀hydrocarbon substituted with halogen, or C₁₋₂₀ alkoxy.

In Formula 3, L is a neutral or cationic Lewis acid, [L-H]⁺ and [L]⁺ aBrönsted acid, Z is a group 13 element; and A is each independentlysubstituted or unsubstituted C₆₋₂₀ aryl or substituted or unsubstitutedC₁₋₂₀ alkyl.

Specifically, the compound represented by Formula 1 is at least oneselected from the group consisting of methylaluminoxane,ethylaluminoxane, isobutylaluminoxane, and butylaluminoxane.

In addition, the compound represented by Formula 2 is at least oneselected from the group consisting of trimethylaluminum,triethylaluminum, triisobutylaluminum, tripropylaluminum,tributylaluminum, dimethylchloroaluminum, triisopropylaluminum,tri-s-butylaluminum, tricyclopentylaluminum, tripentylaluminum,triisopentyaluminum, trihexyaluminum, trioctyaluminum,ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum,tri-p-tolylaluminum, dimethylaluminummethoxide,dimethylaluminumethoxide, trimethylboron, triethylboron,triisobutylboron, tripropylboron, and tributylboron.

In addition, the compound represented by Formula 3 is at least oneselected from the group consisting of triethylammoniumtetraphenylborate, tributylammonium tetraphenylborate, trimethylammoniumtetraphenylborate, tripropylammonium tetraphenylborate,trimethylammonium tetra(p-tolyl)borate, trimethylammoniumtetra(o,p-dimethylphenyl)borate, tributylammoniumtetra(p-trifluoromethylphenyl)borate, trimethylammoniumtetra(p-trifluoromethylphenyl)borate, tributylammoniumtetrapentafluorophenylborate, N,N-diethylanilinium tetraphenylborate,N,N-diethylanilinium tetrapentafluorophenylborate, diethylammoniumtetrapentafluorophenylborate, triphenylphosphonium tetraphenylborate,trimethylphosphonium tetraphenylborate, triethylammoniumtetraphenylaluminate, tributylammonium tetraphenylaluminate,trimethylammonium tetraphenylaluminate, tripropylammoniumtetraphenylaluminate, trimethylammonium tetra(p-tolyl)aluminate,tripropylammonium tetra(p-tolyl)aluminate, triethylammoniumtetra(o,p-dimethylphenyl)aluminate, tributylammoniumtetra(p-trifluoromethylphenyl)aluminate, trimethylammoniumtetra(p-trifluoromethylphenyl)aluminate, tributylammoniumtetrapentafluorophenylaluminate, N,N-diethylaniliniumtetraphenylaluminate, N,N-diethylaniliniumtetrapentafluorophenylaluminate, diethylammoniumtetrapentatetraphenylaluminate, triphenylphosphoniumtetraphenylaluminate, trimethylphosphonium tetraphenylaluminate,tripropylammonium tetra(p-tolyl)borate, triethylammoniumtetra(o,p-dimethylphenyl)borate, tributylammoniumtetra(p-trifluoromethylphenyl)borate, triphenylcarboniumtetra(p-trifluoromethylphenyl)borate, and triphenylcarboniumtetrapentafluorophenylborate.

Preferably, the catalyst for olefin polymerization further comprises acarrier for supporting the first transition metal compound, the secondtransition metal compound, or both. specifically, the carrier maysupport all of the first transition metal compound, the secondtransition metal compound, and the cocatalyst.

Here, the total amount of the first transition metal compound and thesecond transition metal compound supported on the carrier is 0.001 mmoleto 1 mmole based on 1 g of the carrier, and the amount of the cocatalystcompound supported on the carrier is 2 mmoles to 15 mmoles based on the1 g of the carrier.

Specifically, the carrier may comprise at least one selected from thegroup consisting of silica, alumina, and magnesia.

Preferably, the catalyst for olefin polymerization may be a hybridsupported catalyst in which the first transition metal compound and thesecond transition metal compound are supported together. Morepreferably, it may be a hybrid supported catalyst in which the firsttransition metal compound and the second transition metal compound aresupported together on a single carrier.

Specifically, the catalyst for olefin polymerization is a hybridsupported catalyst in which the first transition metal compound, thesecond transition metal compound, and the cocatalyst compound aresupported together on silica.

Advantageous Effects of the Invention

The hybrid metallocene catalyst for olefin polymerization according toan embodiment of the present invention can provide a polyolefin,particularly a linear low-density polyolefin, having excellentprocessability, impact strength, and haze.

BRIEF DESCRIPTION OF THE DRAWING

FIGS. 1a and 1b are GPC-FTIR graphs for measuring the BOCD index of thepolyolefins of Examples 1 and 2 of the present invention, respectively.

FIG. 2 is a graph for measuring the melt strength of the polyolefins ofthe Examples and Comparative Examples of the present invention.

FIG. 3 is a graph showing the complex viscosity with respect to thefrequency of the polyolefins of the Examples and Comparative Examples ofthe present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail.

Catalyst for Olefin Polymerization

The catalyst for olefin polymerization according to an embodiment of thepresent invention comprises a first transition metal compoundrepresented by Formula A and a second transition metal compoundrepresented by Formula B.

In Formulae A and B, n and o are each an integer of 0 to 2, providedthat at least one of them is not 0, and m and 1 are each an integer of 0to 4. Specifically, n and o may each be 1 or 2, and m and 1 may each be1.

M is titanium (Ti), zirconium (Zr), or hafnium (Hf). Specifically, M maybe zirconium (Zr).

X is each independently halogen, C₁₋₂₀ alkyl, C₂₋₂₀ alkenyl, C₂₋₂₀alkynyl, C₆₋₂₀ aryl, C₁₋₂₀ alkyl C₆₋₂₀ aryl, C₆₋₂₀ aryl C₁₋₂₀ alkyl,C₁₋₂₀ alkylamido, C₆₋₂₀ arylamido, or C₁₋₂₀ alkylidene. Specifically, Xmay each be halogen. More specifically, X may each be chlorine (Cl).

Q is carbon (C), silicon (Si), germanium (Ge), or tin (Sn).Specifically, Q may be carbon (C).

R¹ to R⁷ are each independently substituted or unsubstituted C₁₋₂₀alkyl, substituted or unsubstituted C₂₋₂₀ alkenyl, substituted orunsubstituted C₆₋₂₀ aryl, substituted or unsubstituted C₁₋₂₀ alkyl C₆₋₂₀aryl, substituted or unsubstituted C₆₋₂₀ aryl C₁₋₂₀ alkyl, substitutedor unsubstituted C₁₋₂₀ heteroalkyl, substituted or unsubstituted C₃₋₂₀heteroaryl, substituted or unsubstituted C₁₋₂₀ alkylamido, substitutedor unsubstituted C₆₋₂₀ arylamido, substituted or unsubstituted C₁₋₂₀alkylidene, or substituted or unsubstituted C₁₋₂₀ silyl. Here, at leastone of R¹ and R² is independently linked to adjacent groups to form asubstituted or unsubstituted saturated or unsaturated C₄₋₂₀ ring. Inaddition, R³ to R₇ may each independently be linked to adjacent groupsto form a substituted or unsubstituted saturated or unsaturated C₄₋₂₀ring.

Specifically, at least one of R¹ and R² may independently be linked toadjacent groups to form a substituted or unsubstituted saturated orunsaturated C₄₋₂₀ ring. More specifically, R¹ and R² are each linked toadjacent groups to form an unsubstituted unsaturated C₄ ring.

Specifically, R³ may be C₁₋₂₀ alkyl. More specifically, R³ may be C₁₋₆alkyl. Preferably, R³ is n-butyl.

Specifically, R⁴ and R⁵ may each be C₁₋₂₀ alkyl. More specifically, R⁴and R⁵ may each be C₁₋₆ alkyl. Preferably, R⁴ and R⁵ are each t-butyl.

Specifically, R⁶ and R⁷ may each be C₆₋₂₀ aryl. More specifically, R⁶and R⁷ may each be phenyl.

In a preferred embodiment of the present invention, the compoundrepresented by Formula A may be a compound represented by Formula A-1.In addition, the compound represented by Formula B may be a compoundrepresented by Formula B-1.

The catalyst for olefin polymerization according to an embodiment of thepresent invention may comprise the first transition metal compound andthe second transition metal compound at a weight ratio of 20:1 to 1:20.Preferably, the catalyst for olefin polymerization may comprise thefirst transition metal compound and the second transition metal compoundat a weight ratio of 10:1 to 1:10. More preferably, the catalyst forolefin polymerization may comprise the first transition metal compoundand the second transition metal compound at a weight ratio of 6:4 to4:6. When the content ratio of the first transition metal compound andthe second transition metal compound is within the above range, anappropriate activity of the supported catalyst may be exhibited, whichmay be advantageous from the viewpoint of maintaining the activity ofthe catalyst and economical efficiency. Further, a polyolefin preparedin the presence of the catalyst for polymerizing olefin, which satisfiesthe above range, has excellent processability, and a film preparedtherefrom may have excellent strength and haze.

In general, it is known that polyolefins containing a small amount ofshort chain branches (SCBs) have poor optical properties, andpolyolefins containing a large amount of long chain branches (LCBs) haveexcessively high elasticity, thereby having poor mechanical properties.

Polyolefins prepared by the first transition metal compound alonecontain a small amount of short chain branches and are relatively poorin optical properties. Polyolefins prepared by the second transitionmetal compound alone have a large amount of short chain branches andlong chain branches, whereby they are excellent in optical properties,whereas they are relatively poor in mechanical properties. That is, itis confirmed in experimental ways that it is difficult to satisfy bothoptical and mechanical properties when any of the first transition metalcompound and the second transition metal compound is used alone, or whenthe ratio of either the first transition metal compound or the secondtransition metal compound is excessively high.

In contrast, a catalyst for olefin polymerization, which comprises thefirst transition metal compound and the second transition metal compoundat a weight ratio of 0.4:1 to 2.5:1 can produce a polyolefin havingexcellent strength and haze.

As a preferred example, the catalyst for olefin polymerization accordingto an embodiment of the present invention may further comprise acocatalyst compound.

Here, the cocatalyst compound may comprise at least one of a compoundrepresented by Formula 1, a compound represented by Formula 2, and acompound represented by Formula 3.

In Formula 1, n is an integer of 2 or more, and R_(a) may eachindependently be halogen, C₁₋₂₀ hydrocarbon, or C₁₋₂₀ hydrocarbonsubstituted with halogen. Specifically, R_(a) may be methyl, ethyl,n-butyl, or isobutyl.

In Formula 2, D is aluminum (Al) or boron (B), and R_(b), R_(c), andR_(d) are each independently halogen, C₁₋₂₀ hydrocarbon, C₁₋₂₀hydrocarbon substituted with halogen, or C₁₋₂₀ alkoxy. Specifically,when D is aluminum (Al), R_(b), R_(c), and R_(d) may each independentlybe methyl or isobutyl, and when D is boron (B), R_(b), R_(c), and R_(d)may each be pentafluorophenyl.

[L-H]⁺[Z(A)₄]⁻ or [L]⁺[Z(A)₄]⁻  [Formula 3]

In Formula 3, L is a neutral or cationic Lewis acid, [L-H]⁺ and [L]⁺ aBrönsted acid, Z is a group 13 element, and A is each independentlysubstituted or unsubstituted C₆₋₂₀ aryl or substituted or unsubstitutedC₁₋₂₀ alkyl. Specifically, [LH]⁺ may be a dimethylanilinium cation,[Z(A)₄]⁻ may be [B(C₆F₅)₄]⁻, and [L]⁺ may be [(C₆H₅)₃C]⁺.

Examples of the compound represented by Formula 1 includemethylaluminoxane, ethylaluminoxane, isobutylaluminoxane,butylaluminoxane, and the like. Preferred is methylaluminoxane. But itis not limited thereto.

Examples of the compound represented by Formula 2 includetrimethylaluminum, triethylaluminum, triisobutylaluminum,tripropylaluminum, tributylaluminum, dimethylchloroaluminum,triisopropylaluminum, tri-s-butylaluminum, tricyclopentylaluminum,tripentylaluminum, triisopentyaluminum, trihexyaluminum,trioctyaluminum, ethyldimethylaluminum, methyldiethylaluminum,triphenylaluminum, tri-p-tolylaluminum, dimethylaluminummethoxide,dimethylaluminumethoxide, trimethylboron, triethylboron,triisobutylboron, tripropylboron, and tributylboron. Preferred aretrimethylaluminum, triethylaluminum, and triisobutylaluminum. But it isnot limited thereto.

Examples of the compound represented by Formula 3 includetriethylammonium tetraphenylborate, tributylammonium tetraphenylborate,trimethylammonium tetraphenylborate, tripropylammoniumtetraphenylborate, trimethylammonium tetra(p-tolyl)borate,trimethylammonium tetra(o,p-dimethylphenyl)borate, tributylammoniumtetra(p-trifluoromethylphenyl)borate, trimethylammoniumtetra(p-trifluoromethylphenyl)borate, tributylammoniumtetrapentafluorophenylborate, N,N-diethylanilinium tetraphenylborate,N,N-diethylanilinium tetrapentafluorophenylborate, diethylammoniumtetrapentafluorophenylborate, triphenylphosphonium tetraphenylborate,trimethylphosphonium tetraphenylborate, triethylammoniumtetraphenylaluminate, tributylammonium tetraphenylaluminate,trimethylammonium tetraphenylaluminate, tripropylammoniumtetraphenylaluminate, trimethylammonium tetra(p-tolyl)aluminate,tripropylammonium tetra(p-tolyl)aluminate, triethylammoniumtetra(o,p-dimethylphenyl)aluminate, tributylammoniumtetra(p-trifluoromethylphenyl)aluminate, trimethylammoniumtetra(p-trifluoromethylphenyl)aluminate, tributylammoniumtetrapentafluorophenylaluminate, N,N-diethylaniliniumtetraphenylaluminate, N,N-diethylaniliniumtetrapentafluorophenylaluminate, diethylammoniumtetrapentatetraphenylaluminate, triphenylphosphoniumtetraphenylaluminate, trimethylphosphonium tetraphenylaluminate,tripropylammonium tetra(p-tolyl)borate, triethylammoniumtetra(o,p-dimethylphenyl)borate, tributylammoniumtetra(p-trifluoromethylphenyl)borate, triphenylcarboniumtetra(p-trifluoromethylphenyl)borate, and triphenylcarboniumtetrapentafluorophenylborate.

As a preferred example, the catalyst for olefin polymerization accordingto an embodiment of the present invention may further comprise a carrierfor supporting the first transition metal compound, the secondtransition metal compound, or both. Preferably, the catalyst for olefinpolymerization may further comprise a carrier for supporting all of thefirst transition metal compound, the second transition metal compound,and the cocatalyst compound.

In such an event, the carrier may comprise a material containing ahydroxyl group on its surface. Preferably, a material that has beendried to remove moisture from its surface and has a highly reactivehydroxyl group and a siloxane group may be used. For example, thecarrier may comprise at least one selected from the group consisting ofsilica, alumina, and magnesia. Specifically, silica, silica-alumina, andsilica-magnesia dried at high temperatures may be used as a carrier.They usually contain oxides, carbonates, sulfates, and nitratescomponents such as Na₂O, K₂CO₃, BaSO₄, and Mg(NO₃)₂. In addition, theymay comprise carbon, zeolite, magnesium chloride, and the like. However,the carrier is not limited thereto. It is not particularly limited aslong as it can support the first and second transition metal compoundsand the cocatalyst compound.

As a method of supporting the transition metal compounds and thecocatalyst compound employed in a catalyst for olefin polymerization onthe carrier, a physical adsorption method or a chemical adsorptionmethod may be used.

For example, the physical adsorption method may be a method ofcontacting a solution in which a transition metal compound has beendissolved with a carrier and then drying the same; a method ofcontacting a solution in which a transition metal compound and acocatalyst compound have been dissolved with a carrier and then dryingthe same; or a method of contacting a solution in which a transitionmetal compound has been dissolved with a carrier and then drying thesame to prepare the carrier that supports the transition metal compound,separately contacting a solution in which a cocatalyst compound has beendissolved with a carrier and then drying the same to prepare the carrierthat supports the cocatalyst compound, and then mixing them.

The chemical adsorption method may be a method of supporting acocatalyst compound on the surface of a carrier, and then supporting atransition metal compound on the cocatalyst compound; or a method ofcovalently bonding a functional group on the surface of a carrier (e.g.,a hydroxy group (—OH) on the silica surface in the case of silica) witha catalyst compound.

The total amount of the first transition metal compound and the secondtransition metal compound supported on a carrier may be 0.001 mmole to 1mmole based on 1 g of the carrier. When the content ratio of thetransition metal compounds and the carrier satisfies the above range, anappropriate activity of the supported catalyst may be exhibited, whichis advantageous from the viewpoint of maintaining the activity of thecatalyst and economical efficiency.

The amount of the cocatalyst compound supported on a carrier may be 2mmoles to 15 mmoles based on the 1 g of the carrier. When the contentratio of the cocatalyst compound and the carrier satisfies the aboverange, it is advantageous from the viewpoint of maintaining the activityof the catalyst and economical efficiency.

One or two or more types of a carrier may be used. For example, both thefirst transition metal compound and the second transition metal compoundmay be supported on one type of a carrier, or the first transition metalcompound and the second transition metal compound may be supported ontwo or more types of a carrier, respectively. In addition, either one ofthe first transition metal compound and the second transition metalcompound may be supported on a carrier.

Preferably, the catalyst for olefin polymerization may a hybridsupported catalyst in which the first transition metal compound and thesecond transition metal compound are supported together. Morepreferably, it may a hybrid supported catalyst in which the firsttransition metal compound and the second transition metal compound aresupported together on a single carrier.

For example, the catalyst for olefin polymerization may be a hybridsupported catalyst in which the first transition metal compound, thesecond transition metal compound, and the cocatalyst compound aresupported together on silica. However, the examples of the presentinvention are not limited thereto.

According to another embodiment of the present invention, there isprovided a polyolefin prepared by polymerizing an olefinic monomer inthe presence of the catalyst for olefin polymerization described above.

Here, the polyolefin may be a homopolymer of an olefinic monomer or acopolymer of an olefinic monomer and an olefinic comonomer.

The olefinic monomer is at least one selected from the group consistingof a C₂₋₂₀ alpha-olefin, a C₁₋₂₀ diolefin, a C₃₋₂₀ cycloolefin, and aC₃₋₂₀ cyclodiolefin.

For example, the olefinic monomer may be ethylene, propylene, 1-butene,1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene,1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, or the like, andthe polyolefin may be a homopolymer comprising only one olefinic monomeror a copolymer comprising two or more olefinic monomers exemplifiedabove.

As an exemplary example, the polyolefin may be a copolymer in whichethylene and a C₃₋₂₀ alpha-olefin are copolymerized. Preferred is acopolymer in which ethylene and 1-hexene are copolymerized. But it isnot limited thereto.

In such an event, the content of ethylene is preferably 55 to 99.9% byweight, more preferably 90 to 99.9% by weight. The content of thealpha-olefinic comonomer is preferably 0.1 to 45% by weight, morepreferably 0.1 to 10% by weight.

The polyolefin according to an embodiment of the present invention maybe prepared by polymerization reaction such as free radical, cationic,coordination, condensation, and addition, but it is not limited thereto.

As a preferred example, the polyolefin may be prepared by a gas phasepolymerization method, a solution polymerization method, a slurrypolymerization method, or the like. When the polyolefin is prepared by asolution polymerization method or a slurry polymerization method,examples of a solvent that may be used include C₅₋₁₂ aliphatichydrocarbon solvents such as pentane, hexane, heptane, nonane, decane,and isomers thereof; aromatic hydrocarbon solvents such as toluene andbenzene; hydrocarbon solvents substituted with chlorine atoms such asdichloromethane and chlorobenzene; and mixtures thereof, but it is notlimited thereto.

Polyolefin

The polyolefin according to an embodiment of the present inventionsatisfies (1) a molecular weight distribution represented as apolydispersity index (Mw/Mn) of 5 to 20, (2) a density of 0.910 to 0.930g/cm3, (3) a melt index of 0.5 to 2.0 g/10 minutes when measured at 190°C. under a load of 2.16 kg, and (4) a melt index ratio(MI_(21.6)/MI_(2.16)) of 20 to 30.

The polyolefin is prepared in the presence of the hybrid supportedcatalyst for olefin polymerization as described above and has arelatively wide molecular weight distribution. Specifically, thepolyolefin has a molecular weight distribution represented as apolydispersity index (Mw/Mn) of 5 to 20. Preferably, the molecularweight distribution represented as a polydispersity index (Mw/Mn) of thepolyolefin may be 6 to 15. Since the polyolefin has a relatively widemolecular weight distribution, the polyolefin exhibits excellentprocessability, whereby a film obtained therefrom may have good impactresistance.

The polyolefin is a low-density polyethylene copolymer having a densityin the range of 0.910 to 0.930 g/cm3. Preferably, the density of thepolyolefin is in the range of 0.915 to 0.925 g/cm3. If the density ofthe polyolefin is within the above range, a film obtained from thepolyolefin may have good impact resistance.

In the preparation of the polyolefin according to an embodiment of thepresent invention, the density of the polyolefin may be adjusted by thecontent of alpha-olefin, preferably 1-hexene, relative to the content ofethylene. For example, the lower the content of alpha-olefin relative toethylene, the higher the density. The higher the content ofalpha-olefin, the lower the density. Thus, a polyolefin having a densitywithin the above range may be prepared by adjusting the content ofalpha-olefin relative to the content of ethylene in the polyolefin.

The polyolefin of the present invention has a melt index of 0.5 to 2.0g/10 minutes when measured at 190° C. under a load of 2.16 kg accordingto ASTM D1238. Preferably, the melt index of the polyolefin is in therange of 0.5 to 1.5 g/10 minutes when measured at 190° C. under a loadof 2.16 kg. If the melt index of the polyolefin is within the aboverange, it is possible to balance the processability of the polyolefinand the mechanical properties of a film obtained therefrom.

The polyolefin of the present invention has a melt flow ratio (MFR) of20 to 30, which is a value obtained by dividing the melt index measuredat 190° C. under a load of 21.6 kg by the melt index measured at 190° C.under a load of 2.16 kg according to ASTM D1238. Preferably, the MFR ofthe polyolefin is in the range of 22 to 26. If the MFR of the polyolefinis within the above range, it exhibits excellent processability and isparticularly suitable for preparing a blown film.

The polyolefin according to an embodiment of the present invention mayhave a weight average molecular weight (Mw) of 50,000 to 250,000 g/mole.Preferably, the weight average molecular weight (Mw) may be 70,000 to150,000 g/mole. Here, the weight average molecular weight is a valuemeasured using gel permeation chromatography (GPC) and converted basedon standard polystyrene. If the weight average molecular weight of thepolyolefin is within the above range, the mechanical properties of afilm produced therefrom may be good.

The polyolefin according to an embodiment of the present invention mayhave a BOCD index of 0 to 3.0.

Here, the BOCD index refers to a measure of how many short chainbranches having 2 to 6 carbon atoms attached to the main chain of apolymer are present in a relatively high molecular weight component. Ifthe BOCD index is 0 or less, it is not a polymer having a BOCDstructure. If it is greater than 0, it may be regarded as a polymerhaving a BOCD structure.

The molecular weight, molecular weight distribution, and content ofshort chain branches of a polymer may be measured simultaneously andcontinuously using a GPC-FTIR device. The BOCD index may be calculatedby the following Equation 1 by measuring the content of short chainbranches (unit: number/1000 C) in the 30% range of left and right (60%in total) in the molecular weight distribution (MWD) based on weightaverage molecular weight (Mw).

BOCD index=(content of short chain branches in the high-molecular weightcomponent−content of short chain branches in the low-molecular weightcomponent)/(content of short chain branches in the low-molecular weightcomponent)  [Equation 1]

In a polymer having a BOCD structure, tie molecules such as short chainbranches are more present in the high molecular weight component that isrelatively responsible for physical properties than the low molecularweight component, whereby it may have excellent physical properties suchas impact strength.

The polyolefin according to an embodiment of the present invention mayhave a content of long chain branches of 0.01 to 0.1 per 10,000 carbonatoms.

A long chain branch refers to a long branch having 7 or more carbonatoms attached to the main chain of a polyolefin. It is usually formedwhen such an alpha-olefin as 1-butene, 1-hexene, and 1-octene is used asa comonomer.

Since long chain branches give rise to the physical effect of fillingthe voids between polymers, they are known to affect the viscosity andelasticity of a molten polymer in general. If long chain branchesincrease in the polymer chain, causing an increase in the entanglementof the polymer chain, the intrinsic viscosity at the same molecularweight is lowered, which lowers the load on the screw during extrusionand injection, resulting in better workability.

In the present invention, long chain branches of the polyolefin may bemeasured by the method described in Macromolecules, Vol. 33, No. 29, pp.7481-7488 (2000).

The molecular weight distribution (MWD) value is fitted through thecomplex viscosity measured using MCR702 of Anton Parr, and the maximumpeak value is taken. The maximum value of MWD through 3D-GPC is taken.It is then determined from the ratio thereof whether long chainbranching is or not. If the ratio is less than 1, the long chainbranching value is 0 (Relationship 1a below). If it exceeds 1, thecalculated value of Relationship 1b below is taken.

$\begin{matrix}{{\frac{LCB}{10^{4}\mspace{14mu} C} = {\frac{{GPC}\mspace{14mu}{peak}}{{v{iscosity}}{\mspace{11mu}\;}{peak}} < 1}},0} & \lbrack {{Relationship}\mspace{14mu} 1a} \rbrack \\{{\frac{LCB}{10^{4}\mspace{14mu} C} = {\frac{{GPC}\mspace{14mu}{peak}}{{v{iscosity}}\mspace{14mu}{peak}} < 1}},{1.125\mspace{14mu}{\log( \frac{{GPC}\mspace{14mu}{peak}}{{viscosity}\mspace{14mu}{peak}} )}}} & \lbrack {{Relationship}\mspace{14mu} 1b} \rbrack\end{matrix}$

The polyolefin according to an embodiment of the present invention isexcellent in melt strength.

When a film is prepared by blowing air into a molten polyolefin to moldthe polyolefin into a blown film, bubble stability refers to a featurethat the film thus prepared maintains its shape without tearing. Thebubble stability is associated with the melt strength.

Melt strength refers to the strength to withstand tension when a polymerin a molten or softened state is processed such as blowing orstretching. The polyolefin of the present invention can exhibit highmelt strength since a relatively large number of short chain branchesare present in the high molecular weight component, and long chainbranches are also attached to the main chain of the polymer.

The polyolefin according to an embodiment of the present invention has ac₂ value of −0.3 to −0.2 when a graph of the complex index (Pa·s) withrespect to the frequency (rad/s) is fitted with the power law of thefollowing Equation 2.

y=c ₁ x ^(c) ²   [Equation 2]

A polymer in a molten state has properties that are in between a fullyelastic material and a viscous liquid, which is called viscoelasticity.That is, when a polymer in a molten state is subjected to shear stress,the deformation is not proportional to the shear stress, and theviscosity changes according to the shear stress. These properties areunderstood to be attributable to the large molecular size and complexintermolecular structure of the polymer.

In particular, when a polymer is used to prepare a molded article, theshear thinning phenomenon is of importance. The shear thinningphenomenon refers to a phenomenon in which the viscosity of a polymerdecreases as the shear rate increases. Such shear thinningcharacteristics have a great impact on the molding method of a polymer.

Equation 2 above is a model for quantitatively evaluating the shearthinning characteristics of a polyolefin and also for predicting thecomplex viscosity at a high frequency by applying complex viscosity datawith respect to the frequency. In Equation 2, x denotes a frequency, ydenotes a complex viscosity, and the two variables c₁ denotes aconsistency index, and c₂ denotes a CV index, which represents the slopeof the graph. The higher the complex viscosity at a low frequency, thebetter the physical properties, and the lower the complex viscosity at ahigher frequency, the better the processability. Thus, the smaller thevalue of c₂, that is, the larger the negative slope of the graph, themore preferable.

The complex viscosity with respect to the frequency may be measuredusing, for example, MCR702 of Anton Parr in a frequency range of 0.1 to500 rad/s and a strain condition of 5% at 190° C.

The polyolefin according to an embodiment of the present invention has ashear thinning index of 10 to 15 as defined by the following Equation 3.

Shear thinning index=η₀/η₅₀₀  [Equation 3]

In Equation 3, η₀ is the complex viscosity at a frequency of 0.1 rad/s,and η₅₀₀ is the complex viscosity at a frequency of 500 rad/s.

The larger the shear thinning index, the higher the complex viscosity ata low frequency and the lower the complex viscosity at a higherfrequency. Thus, the physical properties and processability of thepolymer may be excellent.

Film

According to still another embodiment of the present invention, there isprovided a film molded from the polyolefin.

The film according to an embodiment of the present invention comprisesthe polyolefin of the present invention, Thus, it is excellent inoptical properties such as haze and in mechanical properties such asimpact strength. It is understood that since the polyolefin of thepresent invention has a relatively wide molecular weight distribution,and since short chain branches are relatively more present in the highmolecular weight component, a film produced therefrom is excellent inhaze and impact resistance.

Specifically, the film according to an embodiment of the presentinvention has a haze of 10% or less and a drop impact strength of 600 gor more.

As an exemplary example, the film of the present invention has a haze of8% or less, preferably 7% or less, and more preferably 6.5% or less.

In addition, the film of the present invention has a drop impactstrength of 650 g or more, preferably 700 g or more, and more preferably800 g or more.

There is no particular limitation to the method for producing a filmaccording to the embodiment of the present invention, and any methodknown in the technical field of the present invention can be used. Forexample, the polyolefin according to an embodiment of the presentinvention may be molded by a conventional method such as blown filmmolding, extrusion molding, casting molding, or the like to prepare aheat-shrinkable polypropylene film. Blown film molding among the aboveis the most preferred.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention is explained in detail with referenceto the following examples and comparative examples. However, thefollowing examples are intended to further illustrate the presentinvention. The scope of the present invention is not limited theretoonly.

Preparation Example 1

The transition metal compound of Formula A-1 purchased from sPCI wasused without purification, and the transition metal compound of FormulaB-1 was purchased from MCN and used without further purification.

2.7387 g of the compound of Formula A-1 and 3.3741 g of the compound ofFormula B-1 were mixed with 991.69 g of a toluene solution of 10% byweight of methylaluminumoxane (MAO) (Al/Zr=150) in a glove box, whichwas stirred at room temperature for 1 hour. Meanwhile, 250 g of silica(XP2402) was charged to a reactor, and 500 ml of purified toluene wasadded thereto, followed by mixing thereof. Thereafter, the transitionmetal compounds solution was injected into the silica slurry, which wasstirred in an oil bath at 75° C. for 3 hours. The supported catalyst waswashed three times with toluene and dried at 60° C. under vacuum for 30minutes to obtain 355 g of a hybrid supported catalyst in the form of afree-flowing powder.

Preparation Example 2

356 g of a hybrid supported catalyst was obtained in the same manner asin Preparation Example 1, except that 1.8310 g of the compound ofFormula A-1 and 5.0754 g of the compound of Formula B-1 were used.

Preparation Example 3

359 g of a hybrid supported catalyst was obtained in the same manner asin Preparation Example 1, except that 8.5302 g of the compound ofFormula B-1 alone was used.

Example 1

An ethylene/1-hexene copolymer was prepared in the presence of thehybrid supported catalyst obtained in Preparation Example 1 in afluidized-bed gas-phase reactor. The temperature in the reactor wasmaintained in the range of 80 to 90° C., and the degree ofpolymerization of the ethylene/1-hexene copolymer prepared was adjustedby adding hydrogen in addition to ethylene and 1-hexene.

Subsequently, the ethylene/1-hexene copolymer was extruded in anextruder having a screw of 40 mm in diameter, a die of 75 mm indiameter, and a die gap of 2 mm at a screw speed of 80 rpm, and it wasthen subjected to blown film molding at a blow-up ratio of 2.0 to obtaina film having a thickness of 50 μm.

Example 2

An ethylene/1-hexene copolymer was prepared in the same manner as inExample 1, except that the hybrid supported catalyst obtained inPreparation Example 2 was used. Subsequently, it was molded in the samemanner as in Example 1 to obtain a film having a thickness of 50 μm.

Comparative Example 1

An ethylene/1-hexene copolymer was prepared in the same manner as inExample 1, except that the supported catalyst obtained in PreparationExample 3 was used. Subsequently, it was molded in the same manner as inExample 1 to obtain a film having a thickness of 50 μm.

Comparative Example 2

A linear low-density polyethylene (M1810HN) of Hanwha Chemical Corp.manufactured with a single metallocene catalyst was used. This resin wasmolded in the same manner as in Example 1 to obtain a film having athickness of 50 μm.

The reaction conditions such as the pressure of ethylene in the reactorand the molar ratio of the raw material gases added in Examples 1 and 2and Comparative Example 1 are as shown in Table 1 below.

TABLE 1 Ethylene Molar ratio of Molar ratio of pressure1-hexene/ethylene hydrogen/ethylene Catalytic activity (bar) (%) (%)(gPE/gCat · hr) Ex. 1 13.9 1.02 1.45 4,500 Ex. 2 13.1 1.34 0.63 4,870 C.Ex. 1 13.2 0.99 0.76 6,500

Test Example

The physical properties of the resins and films prepared in the Examplesand the Comparative Examples were measured according to the followingmethods and standards. The results are shown in Tables 2 and 3 below.

(1) Melt Index

It was measured at 190° C. under a load of 2.16 kg in accordance withASTM D1238.

(2) Melt Flow Ratio (MFR)

It was measured at 190° C. under a load of 2.16 kg and 21.6 kg inaccordance with ASTM D1238. Their ratio (MI_(21.6)/MI_(2.16)) wascalculated.

(3) Density

It was measured in accordance with ASTM D638.

(4) Molecular Weight and Molecular Weight Distribution

They were measured using gel permeation chromatography-FTIR (GPC-FTIR).

(5) BOCD Index

It was measured using gel permeation chromatography-FTIR (GPC-FTIR).

(6) Number of Long Chain Branches (LCB)

The molecular weight distribution (MWD) value is fitted through thecomplex viscosity measured using MCR702 of Anton Parr, and the maximumpeak value was taken. The maximum value of MWD through 3D-GPC was taken.The number of long chain branches was calculated from the ratio usingEquations 1a and 1b above.

(7) Complex Viscosity with Respect to Frequency

It was measured using MCR702 of Anton Parr in a frequency range of 0.1to 500 rad/s and a strain condition of 5% at 190° C.

(8) Film Processing and Extrusion Load

A blown film was prepared in a film processing machine having a die of75 mmΦ and a die gap of 2 mm using a screw of 40 mmΦ. The screw speedwas set to 80 rpm, and the blow-up ratio (BUR) was fixed to 2 to processa film having a thickness of 50 μm, and the extrusion load at that timewas measured.

(9) Drop Impact Strength (B-Type)

It was measured in accordance with ASTM D1790.

(10) Elmendorf Tear Strength

It was measured in the machine direction (MD) and the transversedirection (TD) in accordance with ASTM D1922.

(11) Tensile Strength

It was measured in the machine direction (MD) and the transversedirection (TD) in accordance with ASTM D882.

(12) Haze

Haze of the blown film was measured in accordance with ASTM D1003.

TABLE 2 Properties of resin Unit Ex. 1 Ex. 2 C. Ex. 1 C. Ex. 2 MI g/10min 0.9 1.0 0.9 1.1 MFR — 22 26 19 16 Density g/cm³ 0.920 0.920 0.9190.919 Mn g/mole 13,700 7,100 36,700 41,900 Mw g/mole 116,000 100,300113,500 109,700 MWD — 8.5 14.0 3.1 2.6 BOCD index — 0.29 0.50 0.14 0.16No. of LCD Count/1,000 C 0.04 0.05 0.05 0 CV index (c₂) — −0.26447−0.28252 −0.24333 −0.20848 Shear thinning — 10.88 12.6 9.10 6.51 indexExtrusion load A 26.0 24.5 27.5 28.5

TABLE 3 Properties of resin Unit Ex. 1 Ex. 2 C. Ex. 1 C. Ex. 2 Dropimpact strength g 800 >1,000 510 650 Elmendorf tear MD g 320 420 490 490strength TD G 820 910 900 700 Tensile MD kg/cm² 430 450 390 510 strengthTD kg/cm² 500 570 460 520 Haze % 4.9 6.1 10.2 12.2

As can be seen from Tables 2 and 3 and FIGS. 1 to 3, the polyolefinsprepared in the presence of the hybrid supported catalyst prepared inthe Examples of the present invention had a wide molecular weightdistribution, and short chain branches were relatively more present inthe high molecular weight component. They also had long chain branches.By virtue of such structural characteristics, not only is theprocessability of the polyolefins excellent, but also such mechanicalproperties as drop impact strength and such optical properties as hazeare excellent as compared with the films prepared from the polyolefinsof Comparative Examples.

INDUSTRIAL APPLICABILITY

Accordingly, the hybrid supported catalyst according to the embodimentof the present invention can provide a polyolefin that has excellentprocessability, impact strength, and haze. The film made of thispolyolefin can be advantageously used as a stretch film, an overlapfilm, a ramie, a silage wrap, an agricultural film, and the like.

1. A catalyst for olefin polymerization, which comprises a firsttransition metal compound represented by Formula A and a secondtransition metal compound represented by Formula B:

in Formulae A and B, n and o are each an integer of 0 to 2, providedthat at least one of them is not 0, and m and l are each an integer of 0to 4, M is titanium (Ti), zirconium (Zr), or hafnium (Hf), X is eachindependently halogen, C₁₋₂₀ alkyl, C₂₋₂₀ alkenyl, C₂₋₂₀ alkynyl, C₆₋₂₀aryl, C₁₋₂₀ alkyl C₆₋₂₀ aryl, C₆₋₂₀ aryl C₁₋₂₀ alkyl, C₁₋₂₀ alkylamido,C₆₋₂₀ arylamido, or C₁₋₂₀ alkylidene, Q is carbon (C), silicon (Si),germanium (Ge), or tin (Sn), R¹ to R⁷ are each independently substitutedor unsubstituted C₁₋₂₀ alkyl, substituted or unsubstituted C₂₋₂₀alkenyl, substituted or unsubstituted C₆₋₂₀ aryl, substituted orunsubstituted C₁₋₂₀ alkyl C₆₋₂₀ aryl, substituted or unsubstituted C₆₋₂₀aryl C₁₋₂₀ alkyl, substituted or unsubstituted C₁₋₂₀ heteroalkyl,substituted or unsubstituted C₃₋₂₀ heteroaryl, substituted orunsubstituted C₁₋₂₀ alkylamido, substituted or unsubstituted C₆₋₂₀arylamido, substituted or unsubstituted C₁₋₂₀ alkylidene, or substitutedor unsubstituted C₁₋₂₀ silyl, at least one of R¹ and R² is independentlylinked to adjacent groups to form a substituted or unsubstitutedsaturated or unsaturated C₄₋₂₀ ring, and R³ to R⁷ are each independentlycapable of being linked to adjacent groups to form a substituted orunsubstituted saturated or unsaturated C₄₋₂₀ ring.
 2. The catalyst forolefin polymerization of claim 1, wherein in Formulae A and B, n and oare each 1 or 2, m and 1 are each 1, X is each independently halogen, Mis zirconium, Q is carbon, and at least one of R¹ and R² isindependently linked to adjacent groups to form a substituted orunsubstituted unsaturated C₄₋₂₀ ring, R³ to R⁵ are each C₁₋₂₀ alkyl, andR⁶ and R⁷ are each C₆₋₂₀ aryl.
 3. The catalyst for olefin polymerizationof claim 2, the compounds represented by Formulae A and B are compoundsrepresented by Formulae A-1 and B-1, respectively:


4. The catalyst for olefin polymerization of claim 1, which comprisesthe first transition metal compound and the second transition metalcompound at a weight ratio of 20:1 to 1:20.
 5. The catalyst for olefinpolymerization of claim 1, which further comprises a cocatalyst compoundselected from the group consisting of a compound represented by Formula1, a compound represented by Formula 2, and a compound represented byFormula 3:

in Formula 1, n is an integer of 2 or more, and R_(a) is eachindependently a halogen atom, C₁₋₂₀ hydrocarbon, or C₁₋₂₀ hydrocarbonsubstituted with halogen, in Formula 2, D is aluminum (Al) or boron, andR_(b), R_(c), and R_(d) are each independently a halogen atom, C₁₋₂₀hydrocarbon, C₁₋₂₀ hydrocarbon substituted with halogen, or C₁₋₂₀alkoxy, and in Formula 3, L is a neutral or cationic Lewis acid, [L−H]⁺and [L]⁺ a Brönsted acid, Z is a group 13 element, and A is eachindependently substituted or unsubstituted C₆₋₂₀ aryl or substituted orunsubstituted C₁₋₂₀ alkyl.
 6. The catalyst for olefin polymerization ofclaim 5, wherein the compound represented by Formula 1 is at least oneselected from the group consisting of methylaluminoxane,ethylaluminoxane, isobutylaluminoxane, and butylaluminoxane.
 7. Thecatalyst for olefin polymerization of claim 5, wherein the compoundrepresented by Formula 2 is at least one selected from the groupconsisting of trimethylaluminum, triethylaluminum, triisobutylaluminum,tripropylaluminum, tributylaluminum, dimethylchloroaluminum,triisopropylaluminum, tri-s-butylaluminum, tricyclopentylaluminum,tripentylaluminum, triisopentyaluminum, trihexyaluminum,trioctyaluminum, ethyldimethylaluminum, methyldiethylaluminum,triphenylaluminum, tri-p-tolylaluminum, dimethylaluminummethoxide,dimethylaluminumethoxide, trimethylboron, triethylboron,triisobutylboron, tripropylboron, and tributylboron.
 8. The catalyst forolefin polymerization of claim 5, wherein the compound represented byFormula 3 is at least one selected from the group consisting oftriethylammonium tetraphenylborate, tributylammonium tetraphenylborate,trimethylammonium tetraphenylborate, tripropylammoniumtetraphenylborate, trimethylammonium tetra(p-tolyl)borate,trimethylammonium tetra(o,p-dimethylphenyl)borate, tributylammoniumtetra(p-trifluoromethylphenyl)borate, trimethylammoniumtetra(p-trifluoromethylphenyl)borate, tributylammoniumtetrapentafluorophenylborate, N,N-diethylanilinium tetraphenylborate,N,N-diethylanilinium tetrapentafluorophenylborate, diethylammoniumtetrapentafluorophenylborate, triphenylphosphonium tetraphenylborate,trimethylphosphonium tetraphenylborate, triethylammoniumtetraphenylaluminate, tributylammonium tetraphenylaluminate,trimethylammonium tetraphenylaluminate, tripropylammoniumtetraphenylaluminate, trimethylammonium tetra(p-tolyl)aluminate,tripropylammonium tetra(p-tolyl)aluminate, triethylammoniumtetra(o,p-dimethylphenyl)aluminate, tributylammoniumtetra(p-trifluoromethylphenyl)aluminate, trimethylammoniumtetra(p-trifluoromethylphenyl)aluminate, tributylammoniumtetrapentafluorophenylaluminate, N,N-diethylaniliniumtetraphenylaluminate, N,N-diethylaniliniumtetrapentafluorophenylaluminate, diethylammoniumtetrapentatetraphenylaluminate, triphenylphosphoniumtetraphenylaluminate, trimethylphosphonium tetraphenylaluminate,tripropylammonium tetra(p-tolyl)borate, triethylammoniumtetra(o,p-dimethylphenyl)borate, tributylammoniumtetra(p-trifluoromethylphenyl)borate, triphenylcarboniumtetra(p-trifluoromethylphenyl)borate, and triphenylcarboniumtetrapentafluorophenylborate.
 9. The catalyst for olefin polymerizationof claim 1, which further comprises a carrier for supporting the firsttransition metal compound, the second transition metal compound, orboth.
 10. The catalyst for olefin polymerization of claim 9, wherein thecarrier supports all of the first transition metal compound, the secondtransition metal compound, and the cocatalyst.
 11. The catalyst forolefin polymerization of claim 10, wherein the total amount of the firsttransition metal compound and the second transition metal compoundsupported on the carrier is 0.001 mmole to 1 mmole based on 1 g of thecarrier, and the amount of the cocatalyst compound supported on thecarrier is 2 mmoles to 15 mmoles based on the 1 g of the carrier. 12.The catalyst for olefin polymerization of claim 9, wherein the carriercomprises at least one selected from the group consisting of silica,alumina, and magnesia.
 13. The catalyst for olefin polymerization ofclaim 9, which is a hybrid supported catalyst in which the firsttransition metal compound and the second transition metal compound aresupported together.
 14. The catalyst for olefin polymerization of claim9, which is a hybrid supported catalyst in which the first transitionmetal compound and the second transition metal compound are supportedtogether on a single carrier.
 15. The catalyst for olefin polymerizationof claim 9, which is a hybrid supported catalyst in which the firsttransition metal compound, the second transition metal compound, and thecocatalyst compound are supported together on silica.